Hi.. I live in Indonesia, South East Asia near Malaysia. most of the commercial discus breeders live in West Java region, mostly bekasi and jakarta. and they have good water parameter on their well water.
Just do basic.
+ bare bottom tanks
+ no need to paint the background, some breeders just put used styrofoam or white paper between tanks. (some of the breeders paint the background)
+ Free Well Water (TDS = around 60-80), and very cheap Tap water (around 2-5 cents per m3) - Aged + Aeration + filter
+ Cheap Electric Bill
+ no need for heater (around 28-32 C). (heater just for sick fish)
+ Cheap worker, just pay for 150-200 US dollars a month.
+ Cheap tax
+ Just sponge filter
+ Do 90-100% water change once a day or twice a day
+ Cheap food (Mostly Frozen Blood worm and Beefheart)
Good quality discus, low cost
Adult discus 5 inch up = around 50-100 US dollars
younger discus = around 5-40 US dollars
Discus proven pair = around 100-300 US dollars